Electric fuse



A. w. STEELE.

ELECTRIC FUSE.

APPMCATION FILED JULY 5,19l9.

iNVENTOR ATTORNEYS.

UNITED STATES PATENT OFFICE.

ARCHIE W. STEELE, OF BLOOMFIELD, NEW JERSEY, ASSIGNOR T0 WILFORD J'- HAWKINS, OF MONTCLAIR, NEW JERSEY.

ELECTRIC FUSE.

Specification of LettersPatent.

Patented Mar. 30, 1920.

Application filed July 5, 1919. Serial No. 308,841.

To all whom it may concern:

Be it known that I, ARCHIE W. STEELE, a subject of the King of Great Britain, residin at Bloomfield, in the county of Essex, btate of New Jersey, have invented certain new and useful Improvements in Elec-- tric Fuses, (Case A;) and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to Which it appertains to make and use the same.

This invention is directed to the provision of an improved construction for an electric fuse, particularly one of the type constructed to facilitate removal of the parts of a disrupted fuse and the substitution of a new fuse therefor.

The construction constituting the present invention is preferably employed in combination with the construction described and claimed in an application for patent filed by me on May 24, 1919, Serial No. 299,519. The preferred embodiment of the present invention is illustrated in the accompanying drawings, in which Figure 1 is a central longitudinal section of a fuse; Fig. 2 is a similar View, the plane of the section being at right angles to the plane of Fig. 1; Fig. 3 is a transverse section in line 3-3 of Fig. 2; Fig. 4 is a perspective view of one of the parts employed, and Fig. 5 is an elevation of the tube of the fuse.

Referring to these drawings, 6 indicates a tube of insulating material. Within this tube is a unit consisting of a fusible link 7. a strip of insulating material 8 lying parallel to the link 7 and terminals 9 to which the strip 8 and link 7 are secured by bolts 10 and nuts 11. Each of the terminals 9 consists of a strip of metal, preferably copper, which is bent to provide in the intermediate portion thereof a loop 12 of rectangular configuration and ends lying side by side as is shown in Fig. 1. The terminals so formed are assembled with the fuse strip 7 and the insulating strip 8 to form a unit which may be inserted within and removed from the tube 6 as a unit to facilitate the initial assemblage of the fuse and removal of a burned out link 7. Preferably a pin is driven through holes in each terminal 9 and the strip 8 as is indicated at 13 so as to keep these parts from turning relatively when the bolts 10 are tightened and loosened.

In each end of the tube 6 is a slot, the side walls of which are inclined as is shown in Fig. 5. A plate 14 lies ineach of these slots. The length of the complete unit including the terminals 9 is such that the loops 12 at the ends of this unit may receive the plates 14 when the plates are moved into the slots in the ends of the tube.

A pair of end caps 15 inclose the ends of the tube 6 and each of these end caps 15 has a strip 16 of copper secured thereto to coact with the usual switch clips in connecting the fuse in circuit. The end of the end cap 15 has openings therethrough for screws 17 which enter threaded openings in the plate 14. This plate has inclined sides 18 and it is of a width corresponding closely to the width of the inclined slots in the tube 6.

The unit including the fusible strip is assembled as heretofore described and then passed into the tube 6. Then plates 14 are moved lengthwise into the slots in the ends of the tube and through the loops 12 in the ends of the terminals 9 of the fuse unit. Then the end caps carrying the switch blades 16 are passed over the ends of the tube 6 and the screws 17 are inserted through the holes in the end caps and into the threaded openings in .the plates 14. When these.

screws 17 are tightened up they move the plates 14 bodily toward the'ends of the end caps 15. Since the end caps are braced upon the ends of the tube 6 and the plates 14 are of less width than the depth of the slots in the ends of the tube, as the plates 14 are so moved bodily, they grip the outer sides of the loops of the terminals 9 between them and the interior walls of the end caps, pressing the terminals 9 into hard contact with the inner ends of the blades 16 and thus insuring good electrical connection from the fuse strip 7 to the blades 16. Also, the bodily movement of the plates 14 in the slots in the ends of tube 6 results in expansion of the ends of tube 6 by reason of the inclined side walls of the plates 14 and the slots in the ends of the tube. This ex ansion of the ends of the tube results in orcing the material thereof into engagement with the interior surfaces of the end caps so that the end caps are gripped tightly 1n place.

I claim:

1. An electric fuse comprising a tube of insulating material, a fusible link Within the tube, a strip of insulating material paralleling the link, terminals to which the link and strip are secured, each having a loop formed therein, end caps on the tube and means passing through the loops for securing the terminals in position and making electrical connection thereto and to the fusible link secured to the terminals.

2. An electric fuse comprising a tube of insulating material, a fusible link therein, a pair of terminals secured to the fusible link and having loops formed therein, end caps on the tube and members passing through the loops in the terminals for securing the terminals and the fusible link carried thereby in position and making electrical connection to the terminals.

8. A fuse comprising a tube of insulating material having slots in its ends a fusible link within the tube, terminals to which the link is secured having loops formed therein, plates lying in the slots in the tube and passing through the loops in the terminals, end caps on the tubes and means for moving the plates bodily in the slots toward the ends of the end caps to grip the terminals between the plates and the end caps.

at. A fuse comprising a'tube of insulating material having dove-tail slots in its ends, a unit lying within the tube and consisting of a fusible link, a strip of insulating material extending parallel to the link and two terminals each secured to one end of the strip and link, each of the two terminals having a loop formed therein beyond the end of the link and strip, plates extending through the loops of the terminals and lying in said dove-tail slots, end caps on the tube and screws passing through the end caps and entering threaded openings in the plates to move the plates bodily in the said dove-tail slots to grip the terminals between the plates and the end caps and to expand the ends of the tube within the end caps by the coaction of the side walls of the plates with the side walls of the dove-tail slots.

In testimony whereof I aflix my signature.

ARCHIE W. STEELE. 

